Sectional aircraft pontoon



March 30, 1954 c. E ERIKSSON SECTIONAL AIRCRAFT PONTOON Filed March 14, 1952 IN V EN TOR. fl iwg 3m Patented Mar. 30, 1954 UNITED STATES PATENT OFFICE,

2 Claims.

The present invention relates to an improved sectional pontoon for an aircraft said pontoon comprising three consecutive hinged float sections of which the middle section only is provided with means for supporting the aircraft body so that both the front and tail sections are adjustable.

The chief object of the invention is to provide a seaplane pontoon which is capable automatically to raise up over the water surface within a few seconds.

Another object is to provide an aircraft pontoon which can easily and smoothly climb up over the edge of an ice slab floating on the water surface or the edge of a low, snow-covered shore.

One of the essential purposes of the invention is to provide the pontoon according to the invention with means to control the swing angle of a section relatively to the adjacent section.

Other objects and uses of my invention will be apparent according as the following description proceeds, reference being had to the accompanying drawing illustrating a preferred embodiment of the pontoon.

In the drawing:

Fig. 1 is a longitudinal side view of a seaplane, its body supported by two pontoons according to the invention;

Fig. 2 is a plan view of one of the pontoons, and

Figs. 3 and 4 are vertical cross sections along the line III-III and line IV-IV, respectively, in Fig. 1.

According to the embodiment shown in the drawing by way of example the pontoon comprising a front section I, a middle section 2 supporting a body 3 of a seaplane, and a rear section l. Each section consists of a closed box made of aluminum sheet or like metal, the box reenforced in its interior by T or angle bars 5 of the same material. The vertical longitudinal sides of the front section I are turned in forwardly and its bottom is turned up forwardly so as to form a curved stem 6, provided with a steel bar. The front and rear sections are hinged to the middle section 2 so the two end sections are swingable upwardly about transverse axes 1 against the tension of springs 8. The axes 1 are placed at the bottom of the transverse gaps 9, between the sections I, 2 and 2, 4, respectively. The gaps 9, ID are V-shaped upwardly and inclining forwardly. The walls of the gaps 9, ID are provided with abutments II to restrict the upward swing against the tension of the springs 8. Furthermore, the walls of the gaps 9, [0 are connected with chains or links l2 in order to limit the downward swing when the sections have returned by the spring tension to their initial alignment position.

The bottoms l3, M of the middle respectively the rear sections are concaved upwardly between their longitudinal edges along the entire length of each section, the depth of the concavity decreasing continually from the forward end of the section backwardly so the depth of the concavity disappears at the rear end of the section. At high speed of the seaplane the pontoons can automatically raise up at the water surface by the backwardly inclining concavities which form so-called steps.

Furthermore, the V-shaped, forwardly inclining gaps 9, it) between the sections are adapted to catch air at high speed, the air current conducted downwardly in the gaps 9, l0 and along the longitudinal concavities backwardly. These air currents reduce the frictional resistance at high speed.

Numerous practical tests of the pontoons according to the invention have proved that the pontoons can raise automatically on the backwardly inclining so-called steps within four to six seconds at high speed of the seaplane. If the bottoms of the sections are provided with concavities as above the longitudinal bottom edges will be slightly sharpened so they can serve as sleigh runners gliding on the ice and snow surfaces. Due to this fact the pontoons can easily and smoothly climb up over the edge of an ice slab or a low snow-covered shore. The bottom of the front section I of the pontoon can of course be provided with a similar concavity to facilitate the climbing and gliding on ice and snow surfaces.

The swingable front section of the pontoon serves as a shock absorber for reducing the shocks from waves on the water surface and unevennesses on ice and shore surfaces.

When the seaplane is about to leave the water surface the rear sections of the pontoons will run smoothly along the water surface without scraping or digging in the water.

Having thus described my invention what I claim and desire to protect by Letters Patent is:

1. In a sectional aircraft pontoon the combination of a forwardly disposed float section having means for supporting the aircraft thereon and a slanting rear end surface, a rearwardly disposed tail float section having a forwardly inclined front end surface and being hingedly connected to the rear end of said flrstmentioned float section, transverse hinges located near the bottom side of the pontoon for connecting said float sections, means for confining the angular adjustment of said tail section at one position wherein said tail section is aligned with said flrstmentioned float section and at another position wherein said tail section is swung upwardly a predetermined angle relatively to said firstmentioned section, and spring means tending to keep said tail section in alignment with said firstmentioned section, said tail section having an underside forming a step relatively to the underside of said firstmentioned section and being freely swingable against the action of said spring means to automatically adjust itself in accordance with the different conditions occurring during take-off of the aircraft.

2. In a sectional pontoon for an aircraft the combination of three consecutive longitudinal float sections, a front section having a stem portion and a substantially flat and slanting rear end surface, a middle section having a substantially flat and forwardly inclined front end surface facing said rear end surface of said front section and a substantially flat and slanting rear end surface, and a tail section having a substantially flat and forwardly inclined front end surface facing said rear end surface of said middle section, transverse hinges connecting the rear end of said front section to said middle section and the rear end of said middle section to said tail section respectively, said hinges being located near the bottom side of the respective sections and said rear end surfaces forming an acute angle with the direction of movement of the pentoon which is smaller than that formed by said forwardly inclined front end surfaces to allow said front and tail sections to swing upwardly relatively to said middle section, means for limiting the swinging movements of said sections in an aligned position, spring means tending to keep said sections in aligned position, each of said middle and tail sections having the under part of its bottom formed with a hollow compartment tapering in depth towards the rear end of each section and also towards the respective longitudinal edges of said sections whereby consecutive steps are formed at the underside of the pontoon, each of said steps opening forwardly into the respective spaces formed between the facing end surfaces of the respective float sections so as to received air cached by said inclined spaces at the advancing of the pontoon, and means onsaid middle section only for supporting the aircraft thereon so that said front and tail sections are free to automatically adjust themselves in accordance with the different conditions occurring during take-off and alighting of the aircraft.

CARL ERIK ERIKSSON.

References Cited in the file of this patent UNITED STATES PATENTS Italy Sept. 14, 1931 

